package com.shuang.dp15;

class Solution {
    public int combinationSum4(int[] nums, int target) {

        int[] dp = new int[target + 1];
        
        dp[0] = 1;
        
        //题意是排列问题 要先遍历背包再遍历物品 完全背包要从前到后
        for (int i = 0; i <= target; i++) {
            for (int j = 0; j < nums.length; j++) {
                if (i >= nums[j]) {
                    dp[i] += dp[i - nums[j]];
                }
            }
        }
        return dp[target];

    }
}